管道-管道的敷设城市里的给水、排水、供热、供煤气的管道的干线和长距离的输油输气管道大多敷设在地下，而工厂里的工艺管道为便于操作和维修多敷设在地上。管道的通行、支承、坡度与排液排气、补偿、保温与加热、防腐与清洗、识别与涂漆和安全等，无论对于地上敷设还是地下敷设都是重要的问题。
Pipeline-pipeline laying in the city water supply, drainage, heating, gas supply pipeline trunk lines and long-distance oil and gas transmission pipelines are mostly laid underground, while the process pipelines in www.changzhibanjia.cnwww.diteLi.com.cnwww.lantianr.cnwww.ktmfj.cnfactories are laid on the ground www.baodingbaojie.com.cnwww.yfpackaging.com.cnfor easy operation and maintenance. Pipeline passage, support, gradient, drainage and exhaust, compensation, heat preservation and heating, anti-corrosion and cleaning, identification and painting and safety are all important issues for both ground laying and underground laying.